1<?php
  2/**
  3 * Generated classname block support flag.
  4 *
  5 * @package WordPress
  6 * @since 5.6.0
  7 */
  8
  9/**
 10 * Gets the generated classname from a given block name.
 11 *
 12 * @since 5.6.0
 13 *
 14 * @access private
 15 *
 16 * @param string $block_name Block Name.
 17 * @return string Generated classname.
 18 */
 19function wp_get_block_default_classname( $block_name ) {
 20	// Generated HTML classes for blocks follow the `wp-block-{name}` nomenclature.
 21	// Blocks provided by WordPress drop the prefixes 'core/' or 'core-' (historically used in 'core-embed/').
 22	$classname = 'wp-block-' . preg_replace(
 23		'/^core-/',
 24		'',
 25		str_replace( '/', '-', $block_name )
 26	);
 27
 28	/**
 29	 * Filters the default block className for server rendered blocks.
 30	 *
 31	 * @since 5.6.0
 32	 *
 33	 * @param string $class_name The current applied classname.
 34	 * @param string $block_name The block name.
 35	 */
 36	$classname = apply_filters( 'block_default_classname', $classname, $block_name );
 37
 38	return $classname;
 39}
 40
 41/**
 42 * Adds the generated classnames to the output.
 43 *
 44 * @since 5.6.0
 45 *
 46 * @access private
 47 *
 48 * @param WP_Block_Type $block_type Block Type.
 49 * @return array Block CSS classes and inline styles.
 50 */
 51function wp_apply_generated_classname_support( $block_type ) {
 52	$attributes                      = array();
 53	$has_generated_classname_support = block_has_support( $block_type, 'className', true );
 54	if ( $has_generated_classname_support ) {
 55		$block_classname = wp_get_block_default_classname( $block_type->name );
 56
 57		if ( $block_classname ) {
 58			$attributes['class'] = $block_classname;
 59		}
 60	}
 61
 62	return $attributes;
 63}
 64
 65// Register the block support.
 66WP_Block_Supports::get_instance()->register(
 67	'generated-classname',
 68	array(
 69		'apply' => 'wp_apply_generated_classname_support',
 70	)
 71);
 72